GH4169合金加热过程中δ相形态和晶粒尺寸的演化规律

Evolution of δ-phase Morphology and Grain size in GH4169 Alloy During Preheating

进行GH4169合金加热试验，研究了加热过程中合金的δ相形态和平均晶粒尺寸随温度的变化，建立了考虑δ相形态影响的晶粒长大模型。结果表明，GH4169合金δ相的完全固溶温度在1030-1040℃；在试验温度范围内，随温度的升高，8相从针状或短棒状向颗粒状转化；当温度≤1000℃时，晶粒不长大，其平均晶粒尺寸与初始状态相当；当温度〉1000℃时。平均晶粒尺寸随温度升高而迅速增大。

In order to investigate the principle of microstructure evolution during the preheating of IN718 alloy, the specimens were preheated under different temperatures. The average grain size and δ-phase morphology were researched and the grain growth model added the factor of δ-phase morphology was established. The results indicate that the δ-phase can fully dissolve into austenitic matrix by holding temperature between 1030 ℃ and 1040℃. The δ-phase morphology of GH4169 alloy changes from specula or short bars into particles, The grain size of the alloy is equal to the original grain size when preheating temperature is equal or lower than 1000℃. The grain size of the alloy grows up rapidly with temperature increasing, when the preheating temperature is higher than 1000 ℃.